Effect of Polysaccharide Species on Storage Stability of Alginate Capsules Containing <i>α</i>-Tocopherol

Abstract

Alginate capsules containing α-tocopherol were prepared adding polysaccharide species such as κ-carrageenan, gellan gum, pectin, curdlan and ghatti gum. The effects of polysaccharide species and the diameters of α-tocopherol on storage stability of the capsules were investigated and characterized in detail. As the contact angle of α-tocopherol to the capsule shell strongly affected storage stability, the contact angle was measured on the model sheet made of calcium alginate with polysaccharide species. The leakage ratio decreased with the contact angle and increased with the diameter of α-tocopherol. The capsules made of calcium alginate with gellan gum showed the largest contact angle and the highest storage stability. The capsules made of calcium alginate with curdlan, ghatti gum and pectin were harder than other capsules and showed higher storage stability. All the capsules showed the almost similar swelling ratio in the acidic solution with pH 4, but showed the different swelling ratios according to the polysaccharide species in the alkali solution with pH 9. The tablets were prepared with the wet and the dried capsules. The tablets prepared with the dried capsules showed higher storage stability.